From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754482AbcJUGeF (ORCPT ); Fri, 21 Oct 2016 02:34:05 -0400 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:46962 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754323AbcJUGeD (ORCPT ); Fri, 21 Oct 2016 02:34:03 -0400 Date: Fri, 21 Oct 2016 09:33:24 +0300 From: Sakari Ailus To: Thierry Escande Cc: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Pawel Osciak , Marek Szyprowski , Kyungmin Park Subject: Re: [PATCH v3] [media] vb2: Add support for capture_dma_bidirectional queue flag Message-ID: <20161021063324.GY9460@valkosipuli.retiisi.org.uk> References: <1476953764-25145-1-git-send-email-thierry.escande@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1476953764-25145-1-git-send-email-thierry.escande@collabora.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thierry, On Thu, Oct 20, 2016 at 10:56:04AM +0200, Thierry Escande wrote: > From: Pawel Osciak > > When this flag is set for CAPTURE queues by the driver on calling > vb2_queue_init(), it forces the buffers on the queue to be > allocated/mapped with DMA_BIDIRECTIONAL direction flag instead of > DMA_FROM_DEVICE. This allows the device not only to write to the > buffers, but also read out from them. This may be useful e.g. for codec > hardware which may be using CAPTURE buffers as reference to decode > other buffers. > > This flag is ignored for OUTPUT queues as we don't want to allow HW to > be able to write to OUTPUT buffers. > > Signed-off-by: Pawel Osciak > Tested-by: Pawel Osciak > Signed-off-by: Thierry Escande > --- > > Changes since v1: > - Renamed use_dma_bidirectional field as capture_dma_bidirectional > - Added a VB2_DMA_DIR() macro > > Changes since v2: > - Get rid of dma_dir field and therefore squashed the previous patch > > drivers/media/v4l2-core/videobuf2-core.c | 9 +++------ > include/media/videobuf2-core.h | 15 +++++++++++++++ > 2 files changed, 18 insertions(+), 6 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 21900202..22d6105 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -194,8 +194,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb); > static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > { > struct vb2_queue *q = vb->vb2_queue; > - enum dma_data_direction dma_dir = > - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; > + enum dma_data_direction dma_dir = VB2_DMA_DIR(q); > void *mem_priv; > int plane; > int ret = -ENOMEM; > @@ -978,8 +977,7 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb) > void *mem_priv; > unsigned int plane; > int ret = 0; > - enum dma_data_direction dma_dir = > - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; > + enum dma_data_direction dma_dir = VB2_DMA_DIR(q); > bool reacquired = vb->planes[0].mem_priv == NULL; > > memset(planes, 0, sizeof(planes[0]) * vb->num_planes); > @@ -1096,8 +1094,7 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb) > void *mem_priv; > unsigned int plane; > int ret = 0; > - enum dma_data_direction dma_dir = > - q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; > + enum dma_data_direction dma_dir = VB2_DMA_DIR(q); > bool reacquired = vb->planes[0].mem_priv == NULL; > > memset(planes, 0, sizeof(planes[0]) * vb->num_planes); > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index ac5898a..631f08b 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -433,6 +433,9 @@ struct vb2_buf_ops { > * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF > * has not been called. This is a vb1 idiom that has been adopted > * also by vb2. > + * @capture_dma_bidirectional: use DMA_BIDIRECTIONAL for CAPTURE buffers; this > + * allows HW to read from the CAPTURE buffers in > + * addition to writing; ignored for OUTPUT queues. > * @lock: pointer to a mutex that protects the vb2_queue struct. The > * driver can set this to a mutex to let the v4l2 core serialize > * the queuing ioctls. If the driver wants to handle locking > @@ -499,6 +502,7 @@ struct vb2_queue { > unsigned fileio_write_immediately:1; > unsigned allow_zero_bytesused:1; > unsigned quirk_poll_must_check_waiting_for_buffers:1; > + unsigned capture_dma_bidirectional:1; > > struct mutex *lock; > void *owner; > @@ -554,6 +558,17 @@ struct vb2_queue { > #endif > }; > > +/* > + * Return the corresponding DMA direction given the vb2_queue type (capture or > + * output). returns DMA_BIRECTIONAL for capture buffers if the vb2_queue field DMA_BIDIRECTIONAL With that fixed, Acked-by: Sakari Ailus > + * capture_dma_bidirectional is set by the driver. > + */ > +#define VB2_DMA_DIR(q) (V4L2_TYPE_IS_OUTPUT((q)->type) \ > + ? DMA_TO_DEVICE \ > + : (q)->capture_dma_bidirectional \ > + ? DMA_BIDIRECTIONAL \ > + : DMA_FROM_DEVICE) > + > /** > * vb2_plane_vaddr() - Return a kernel virtual address of a given plane > * @vb: vb2_buffer to which the plane in question belongs to -- Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk